1. Field of the Invention
The present invention relates to an ion trap time-of-flight mass spectrometer comprising an ion trap part for trapping ions and a time-of-flight mass spectrometry part.
2. Background Art
The ion trap time-of-flight mass spectrometer is a mass spectrometer in which an ion trap part and a time-of-flight mass spectrometer are connected, and for example, JP Patent Publication (Kokai) No. 2003-123685 A discloses such a spectrometer.
As a mass spectrometer in the biological field, since the molecular weight of a sample to be measured is large, in many cases, the time-of-flight (TOF) mass spectrometer is used.
The time-of-flight (TOF) mass spectrometer is a technique on which a patent was granted in the United States in 1951 (U.S. Pat. No. 2,685,035), and because of recent advances in electronics, it has become a more familiar mass spectrometer. Thus, such spectrometer is widely used in the biological field and the like.
Particularly in the biological field, an ion trap was introduced, and thus a technique having high mass accuracy and enabling MSn analysis has been developed.
According to the technique, such ion trap is introduced between an ion source and a time-of-flight (TOF) mass spectrometer, and in this way, ion isolation or ion dissociation can be repeated inside the ion trap, thereby enabling MSn analysis.
The kinetic energy of the ions discharged from the ion trap is converged in a multipole part, and it is then introduced between a PUSH electrode and a PULL electrode of the time-of-flight (TOF) mass spectrometer.
High-voltage pulses at a constant period are applied to the ions introduced between the PUSH electrode and the PULL electrode, the ions are then introduced into an acceleration region, and as a result, they are accelerated in an orthogonal direction (JP Patent Publication (Kokai) No. 2003-123685 A).
By detecting current values in accordance with ion flight time with an MCP (detecting part), the time-of-flight mass spectrometry for calculating mass spectra is conducted. By disposing an ion introduction direction and acceleration direction so that the directions are orthogonal to each other, high resolution and high mass accuracy can be achieved.